US Grow Zones

Flower Mound, Texas: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00413691); U.S. Census Bureau — see methodology

Flower Mound is in USDA plant hardiness zone 8b, where the average coldest winter night reaches 15 to 20°F (-9.4 to -6.7°C). The typical last spring frost is around Mar 23 and the first fall frost around Nov 9.

Hardiness zone8B15 to 20°F
Last spring frostMar 2330% chance of frost after
First fall frostNov 930% chance of frost before
Growing season249 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Apr 3Nov 2
Typical planning date (30% risk)Mar 23Nov 9
Median (50%)Mar 14Nov 17

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station GRAPEVINE DAM, TX (USC00413691), 6.9 mi (11.1 km) from the city center and 43 ft lower than the city center (-13 m). Record used for the 1991–2020 normals: 22 years.

Frost probability in spring and fall, Flower Mound, TXChance of a 32°F frost in Flower Mound, TX, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Feb 23 to 10% on Apr 3. Fall: the chance that the first frost has arrived rises from 10% on Nov 2 to 90% on Dec 4.0%50%100%Spring: later frostFeb 1Mar 1Apr 130%: Mar 23Fall: frost arrivedNov 1Nov 15Dec 1Dec 1530%: Nov 932°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USC00413691.
Frost-free growing season in Flower Mound, TX1 in 10 risk: Apr 3 to Nov 2 (213 days); 3 in 10 risk: Mar 23 to Nov 9 (231 days); Median (50%): Mar 14 to Nov 17 (248 days); No 28°F freeze: Mar 1 to Nov 29 (273 days). In 9 of 10 years the 32°F-free season is at least 223 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk213 days3 in 10 risk231 daysMedian (50%)248 daysNo 28°F freeze273 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Flower Mound

All 4 ZIP codes covering Flower Mound are in zone 8b.

ZIP codes in Flower Mound and their zones
ZIPZoneShare of city land
750228b43.7%
750288b36.9%
762628b9.4%
762268b9.2%

Vegetable planting calendar for Flower Mound

Dates are counted from the 30%-risk frost dates above (last frost Mar 23, first frost Nov 9). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 26 – Feb 9Mar 30 – Apr 13——
PepperJan 12 – Jan 26Apr 6 – Apr 20——
LettuceFeb 9 – Feb 23Mar 9 – Mar 30Feb 23 – Apr 6Aug 31 – Sep 28
Green Beans——Mar 30 – May 4Aug 17 – Aug 31
Sweet Corn——Mar 30 – Apr 27—
Zucchini & Summer SquashFeb 23 – Mar 2Mar 30 – Apr 13Mar 30 – Apr 20Aug 17 – Aug 31
CucumberFeb 23 – Mar 2Apr 6 – Apr 13Mar 30 – Apr 20Aug 17 – Aug 31
Carrot——Mar 2 – Apr 6Aug 17 – Aug 31
OnionDec 29 – Jan 12Feb 23 – Mar 9——
Potato—Feb 23 – Mar 16——
BasilFeb 9 – Feb 23Apr 6 – Apr 20Apr 6 – Apr 27—
Spinach——Feb 9 – Mar 9Sep 14 – Oct 12
KaleJan 26 – Feb 9Feb 23 – Mar 16Feb 23 – Mar 16Aug 31 – Sep 28
BroccoliJan 26 – Feb 9Mar 9 – Mar 30—Aug 17 – Aug 31
Peas——Feb 9 – Mar 2Aug 31 – Sep 14
EggplantJan 12 – Jan 26Apr 6 – Apr 20——
CabbageJan 26 – Feb 9Feb 23 – Mar 9—Aug 17 – Aug 31
Radish——Feb 16 – Apr 6Sep 28 – Oct 26
Strawberry—Feb 23 – Mar 16——
Beets——Mar 2 – Apr 13Aug 31 – Sep 14

Nearby cities in Texas

More: all Texas cities · other zone 8b cities: Dallas, TX, Fort Worth, TX, El Paso, TX, Virginia Beach, VA, Arlington, TX, Plano, TX, Irving, TX, Garland, TX

Flower Mound gardening questions

When is the last frost in Flower Mound, TX?

Plan around Mar 23. At NOAA's Grapevine Dam, TX station, 6.9 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Mar 14, and after Apr 3 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 1. The 90% and 10% dates are 39 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Flower Mound, TX?

Start seeds indoors Jan 26 – Feb 9 and set transplants outside Mar 30 – Apr 13, once nights stay above 50°F and the soil is near 60°F. That leaves 231 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.

How long is the growing season in Flower Mound?

About 249 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 223 days, and in 1 year in 10 it runs 275 days or more. In fall there is a 10% chance of frost by Nov 2 and a 30% chance by Nov 9. That ranks 44th longest of 55 Texas cities on this site.

When should I plant a fall garden in Flower Mound?

Count back from the first fall frost (Nov 9): transplant broccoli Aug 17 – Aug 31; sow kale Aug 31 – Sep 28; sow lettuce Aug 31 – Sep 28; sow radishes Sep 28 – Oct 26. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 29. How the math works: succession and fall planting.

Did Flower Mound's hardiness zone change on the 2023 map?

Yes. Most of Flower Mound was zone 8a on the 2012 map and is zone 8b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.

How does Flower Mound compare with Denton, TX?

Both are in zone 8b. The typical last spring frost in Flower Mound (Mar 23) comes about the same time as in Denton, TX (Mar 21), 13 miles away, and the first fall frost is Nov 9 versus Nov 12. The two cities use different NOAA stations.